A compound having the structure of

##STR00001##

is disclosed. In the structure of Formula I, each of R.sub.1, R.sub.2, and R.sub.3 is independently a hydrogen, a non-fused aryl group having one meta-substituent, or a non-fused heteroaryl six-membered ring having one or more meta-substituents; each meta-substituent is a non-fused aryl or non-fused heteroaryl six-membered ring optionally substituted with further substituents selected from the group consisting of non-fused aryl groups, non-fused heteroaryl groups, and alkyl groups; and at least one of R.sub.1, R.sub.2, and R.sub.3 is a non-fused aryl having one meta-substituent or a heteroaryl six-membered ring having at least one meta-substituent, wherein each meta-substituent is a non-fused aryl or non-fused heteroaryl group further substituted with a chain of at least two non-fused aryl or non-fused heteroaryl groups. The compounds may be useful in phosphorescent organic light emitting devices.

A compound having the structure of

##STR00001##

is disclosed. In the structure of Formula I, each of R.sub.1, R.sub.2, and R.sub.3 is independently a hydrogen, a non-fused aryl group having one meta-substituent, or a non-fused heteroaryl six-membered ring having one or more meta-substituents; each meta-substituent is a non-fused aryl or non-fused heteroaryl six-membered ring optionally substituted with further substituents selected from the group consisting of non-fused aryl groups, non-fused heteroaryl groups, and alkyl groups; and at least one of R.sub.1, R.sub.2, and R.sub.3 is a non-fused aryl having one meta-substituent or a heteroaryl six-membered ring having at least one meta-substituent, wherein each meta-substituent is a non-fused aryl or non-fused heteroaryl group further substituted with a chain of at least two non-fused aryl or non-fused heteroaryl groups. The compounds may be useful in phosphorescent organic light emitting devices.

A compound represented by the following formula (1):

##STR00001##

The R.sup.1 to R.sup.9, L.sup.1 to L.sup.3, and Ar.sup.1 to Ar.sup.2 in the formula (1) are as defined in the description. An organic electroluminescence device contains the compound, and an electronic instrument includes the organic electroluminescence device.

A compound represented by the following formula (1):

##STR00001##

The R.sup.1 to R.sup.9, L.sup.1 to L.sup.3, and Ar.sup.1 to Ar.sup.2 in the formula (1) are as defined in the description. An organic electroluminescence device contains the compound, and an electronic instrument includes the organic electroluminescence device.

The present disclosure relates to display technologies, and particularly discloses an organic electroluminescent device. This organic electroluminescent device includes a light-emitting layer, the light-emitting includes an exciplex composed of a donor molecule and an acceptor molecule, and a wide band gap material for increasing the inter-molecular spacing between the donor molecule and the acceptor molecule. According to the device of the present disclosure, the degree of orbital overlap of HOMO and LUMO of the formed exciplex and the singlet-triplet energy level difference can be reduced, the reverse intersystem crossing rate (k.sub.RISC) of the exciplex host can be increased, the Föster energy transferred to the guest molecule can be enhanced, and the efficiency and the lifetime of the device can be improved.

The present disclosure relates to display technologies, and particularly discloses an organic electroluminescent device. This organic electroluminescent device includes a light-emitting layer, the light-emitting includes an exciplex composed of a donor molecule and an acceptor molecule, and a wide band gap material for increasing the inter-molecular spacing between the donor molecule and the acceptor molecule. According to the device of the present disclosure, the degree of orbital overlap of HOMO and LUMO of the formed exciplex and the singlet-triplet energy level difference can be reduced, the reverse intersystem crossing rate (k.sub.RISC) of the exciplex host can be increased, the Föster energy transferred to the guest molecule can be enhanced, and the efficiency and the lifetime of the device can be improved.

An organometallic compound represented by Formula 1, which is explained in the specification, is provided. A light-emitting device is provided, which includes a first electrode, a second electrode facing the first electrode, an interlayer between the first electrode and the second electrode and including an emission layer, and the organometallic compound. An electronic apparatus including the light-emitting device is also provided:

##STR00001##

An organometallic compound represented by Formula 1, which is explained in the specification, is provided. A light-emitting device is provided, which includes a first electrode, a second electrode facing the first electrode, an interlayer between the first electrode and the second electrode and including an emission layer, and the organometallic compound. An electronic apparatus including the light-emitting device is also provided:

##STR00001##

A light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode, the interlayer including an emission layer. The emission layer includes a first emission layer including a first host and a second host, and a second emission layer including a third host. A triplet energy T.sub.1_H1 of the first host, a triplet energy T.sub.1_H2 of the second host, and a triplet energy T.sub.1_H3 of the third host satisfy Formulae (1) and (2) as defined below:

T.sub.1_H1−T.sub.1_H3≥0.2 eV  (1),

T.sub.1_H2−T.sub.1_H3≥0.2 eV  (2).

A light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode, the interlayer including an emission layer. The emission layer includes a first emission layer including a first host and a second host, and a second emission layer including a third host. A triplet energy T.sub.1_H1 of the first host, a triplet energy T.sub.1_H2 of the second host, and a triplet energy T.sub.1_H3 of the third host satisfy Formulae (1) and (2) as defined below:

T.sub.1_H1−T.sub.1_H3≥0.2 eV  (1),

T.sub.1_H2−T.sub.1_H3≥0.2 eV  (2).